RESUMO
The coexistence of cultural identities and their interaction is a fundamental topic of social sciences that is not easily addressed in prehistory. Differences in mortuary treatment can help approach this issue. Here, we present a multi-isotope study to track both diet and mobility through the life histories of 32 broadly coeval Late Neolithic individuals interred in caves and in megalithic graves of a restricted region of northern Iberia. The results show significant differences in infant- and child-rearing practices, in subsistence strategies, and in landscape use between burial locations. From this, we posit that the presence of communities with distinct lifestyles and cultural backgrounds is a primary reason for Late Neolithic variability in burial location in Western Europe and provides evidence of an early "them and us" scenario. We argue that this differentiation could have played a role in the building of lasting structures of socioeconomic inequality and, occasionally, violent conflict.
Assuntos
Antropologia Cultural , Cultura , Isótopos , Ciências Sociais , Isótopos de Carbono/análise , Cavernas , Meio Ambiente , Europa (Continente) , Humanos , Isótopos de Nitrogênio/análise , PlantasRESUMO
Rhizobial lipochitooligosaccharide (LCO) signal molecules induce various plant responses, leading to nodule development. We report here the LCO structures of the broadhost range strain Rhizobium sp. BR816. The LCOs produced are all pentamers, carrying common C18:1 or C18:0 fatty acyl chains, N-methylated and C-6 carbamoylated on the nonreducing terminal N-acetylglucosamine and sulfated on the reducing/terminal residue. A second acetyl group can be present on the penultimate N-acetylglucosamine from the nonreducing terminus. Two novel characteristics were observed: the reducing/terminal residue can be a glucosaminitol (open structure) and the degree of acetylation of this glucosaminitol or of the reducing residue can vary.
Assuntos
Lipopolissacarídeos/biossíntese , Lipopolissacarídeos/química , Rhizobium/metabolismo , Configuração de Carboidratos , Sequência de Carboidratos , Cromatografia Líquida de Alta Pressão , Fabaceae/microbiologia , Lipopolissacarídeos/isolamento & purificação , Espectrometria de Massas , Modelos Moleculares , Dados de Sequência Molecular , Oligossacarídeos/química , Plantas Medicinais , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massa de Íon SecundárioRESUMO
Phaseolus vulgaris is a promiscuous host plant that can be nodulated by many different rhizobia representing a wide spectrum of Nod factors. In this study, we introduced the Rhizobium tropici CFN299 Nod factor sulfation genes nodHPQ into Azorhizobium caulinodans. The A. caulinodans transconjugants produce Nod factors that are mostly if not all sulfated and often with an arabinosyl residue as the reducing end glycosylation. Using A. caulinodans mutant strains, affected in reducing end decorations, and their respective transconjugants in a bean nodulation assay, we demonstrated that bean nodule induction efficiency, in decreasing order, is modulated by the Nod factor reducing end decorations fucose, arabinose or sulfate, and hydrogen.
Assuntos
Fabaceae/microbiologia , Lipopolissacarídeos/metabolismo , Plantas Medicinais , Rhizobium/genética , Sequência de Bases , Conjugação Genética , Primers do DNA/genética , Genes Bacterianos , Lipopolissacarídeos/química , Mutação , Rhizobium/metabolismoRESUMO
Rhizobium sp. BR816 contains four nodD alleles of which nodD3 is the most important transcriptional regulator for nodulation of Phaseolus vulgaris. Upstream of nodD3 an open reading frame, orf816, was identified. The deduced ORF816 protein shows homology with transcriptional regulators of the AraC/XylS family. The DNA binding domain and the consensus motif, characteristic of the C-terminal region of the members of this family of transcriptional regulators, are present in the deduced ORF816 protein. Activation of nodA gene expression and nodulation of P. vulgaris by Rhizobium sp. NGR234nodD1::omega (Nod-) complemented with the Rhizobium sp. BR816 nodD3 gene were significantly increased in the presence of orf816. This increased nodulation and nod gene induction are mediated through positive regulation of nodD3 expression by ORF816. Expression of orf816 itself is partially RpoN dependent. The role of this transcriptional regulator in the complex cascade regulation of the Rhizobium sp. nodD3 gene is discussed.
Assuntos
Proteínas de Bactérias/genética , Proteínas de Ligação a DNA , Regulação Bacteriana da Expressão Gênica/genética , Proteínas Repressoras/genética , Rhizobium/genética , Fatores de Transcrição/genética , Fator de Transcrição AraC , RNA Polimerases Dirigidas por DNA/fisiologia , Fabaceae/microbiologia , Genes Bacterianos/fisiologia , Glucuronidase/genética , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Plantas Medicinais , RNA Polimerase Sigma 54 , Proteínas Recombinantes de Fusão , Mapeamento por Restrição , Fator sigma/fisiologia , Transativadores/genética , Ativação TranscricionalRESUMO
The broad-host-range, heat-tolerant Rhizobium strain BR816 produces sulphated Nod metabolites. Two ORFs highly homologous to the Sinorhizobium meliloti nodPQ genes were isolated and sequenced. It was found that Rhizobium sp. BR816 contained two copies of these genes; one copy was localized on the symbiotic plasmid, the other on the megaplasmid. Both nodP genes were interrupted by insertion of antibiotic resistance cassettes, thus constructing a double nodP1P2 mutant strain. However, no detectable differences in Nod factor TLC profile from this mutant were observed as compared to the wild-type strain. Additionally, plant inoculation experiments did not reveal differences between the mutant strain and the wild-type. It is proposed that a third, functionally homologous locus complements mutations in the Nod factor sulphation genes. Southern blot analysis suggested that this locus contains genes necessary for the sulphation of amino acids.
